need advise,please

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three counties
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Joined: Mon Oct 11, 04 9:17 pm
Location: linton,cambridge

need advise,please

Post by three counties »

hi all,a few years ago,i bought a front disc brake set up ,of a mma member,it came of a e body,i have got every thing for it,pair of brake callipers,single piston,discs,brake hoses,and the spindles,these take the 15 inch wheel.my car has the factory fitted brake servo,but with the front brake drums,would like to try and find out if the brake master cylinder ,will be ok,or if I need to change it?or could I adjust the push rod on the brake pedal,also if I need to replace the proportion valve,i have replaced the master cylinder a while ago,have checked both pistons in the callipers,and they are both ok,i have got a good brake flaring kit,if I need to replace any of the brake pipes,the car is a 68 charger,any advice on this please
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Pete
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Re: need advise,please

Post by Pete »

Brake Master Cylinder is the issue. The Servo has no impact.

Drum Brakes MC have valves in them under the tapered seats on the Output ports. This is to keep the shoes near the Drums.

If you use a Drum Brake MC on a Disc brake car, the brakes will pump up and bind on.

Either change to a Disc brake MC or you can carefully remove the tapered seat and take out the shuttle valve under the seat and re-install the tapered Seat.

I have done it; but most people would change the MC for the correct Disc / Drum set up MC.

Thanks

Pete
Pete Wiseman; Cambridge.

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three counties
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Re: need advise,please

Post by three counties »

Thanks Pete for the information, will phone around tomorrow and see what is available in the UK,do you think I might need to change the proportion valve as well,?I did read some where that they could be different, thanks
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Pete
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Re: need advise,please

Post by Pete »

Regarding the Prop valve, it really is a case of trial and error.

At work we tend to fit Wilwood adjustable ones on the rear line to prevent rear wheel lock up.
This is because the Drums tend to operate before the Discs due to the reasons above.
Pete Wiseman; Cambridge.

Mopar by the grace of God
three counties
Posts: 153
Joined: Mon Oct 11, 04 9:17 pm
Location: linton,cambridge

Re: need advise,please

Post by three counties »

Ok thanks, probably be best if I change the proportion valve while I'm doing the brakes, have just been looking on rock auto,and they have got the master cylinder,carnt find the valve on there, like you said, when it is all fitted,and the brakes have been bled,it may need a bit of playing about ,
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morgan
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Re: need advise,please

Post by morgan »

Pete wrote: Mon Feb 24, 20 9:18 pm Regarding the Prop valve, it really is a case of trial and error.

At work we tend to fit Wilwood adjustable ones on the rear line to prevent rear wheel lock up.
This is because the Drums tend to operate before the Discs due to the reasons above.
Yup. Can confirm this. When cold the rears lock before the fronts with Wilwood setup. Better when warm (if less exciting :clown: )
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three counties
Posts: 153
Joined: Mon Oct 11, 04 9:17 pm
Location: linton,cambridge

Re: need advise,please

Post by three counties »

Before I start doing the brake conversion, will have to decide where to fit the willwood adjustable valve,I no it has to be fitted of the proportion valve, will make up a bracket to mount it, probably the best place for it,is near to the master cylinder?I could fit it in the car, but it might be in the way,any ideas , please
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Dave999
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Re: need advise,please

Post by Dave999 »

if you reduce the bore of the rear cylinders

or change from 11 inch to 10 inch rear drum brakes and reduce the bore of the rear cylinders you will help things along nicely.

https://www.ebay.com/itm/for-MOPAR-Disc ... SwY45UN7Km

dave
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three counties
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Re: need advise,please

Post by three counties »

thanks dave,thats good to no,if I get any problems
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